Men with severe hemophilia A showed reduced levels of bone mineral density, compared with controls representative of the general population, according to findings from a case-control study.

In addition, the decrease in bone mineral density (BMD) was correlated with reduced functional ability and body mass index (BMI), and vitamin D insufficiency or deficiency.

“We aimed to investigate the presence of low BMD in adult patients diagnosed with severe hemophilia A and to evaluate the potential risk factors associated with low BMD and musculoskeletal function levels,” wrote Omer Ekinci, MD, of Firat University in Elazig, Turkey, and colleagues in Haemophilia.

The study included 41 men with severe hemophilia A and 40 men without hemophilia who were matched for age. All patients with hemophilia A received regular prophylactic therapy, and one patient had a high titre (greater than 5 Bethesda units) inhibitor against FVIII.

The researchers performed several laboratory tests: BMD was measured using dual-energy x-ray absorptiometry; BMI was recorded; and laboratory tests were performed to ascertain levels of vitamin D, calcium, phosphorus, alkaline phosphatase, parathyroid hormone, and hepatitis C and HIV antibodies. The Functional Independence Score in Hemophilia (FISH) was used to measure functional-ability status only in the study group.

After analysis, the researchers found a significant difference between patients in the case and control groups for femoral neck and total hip BMD (P = .017 and P less than .001, respectively), but not for lumbar spine BMD (P = .071).

In patients with hemophilia aged younger than 50 years, 27.8% were found to have “low normal” BMD levels, and 19.4% showed “lower than expected” BMD levels with respect to age.

“Vitamin D insufficiency and deficiency were present in 63.4% of the patients with hemophilia, significantly higher than the control group [37.5%; P less than .001],” the researchers wrote.

There were also statistically significant positive correlations between FISH score and femoral neck BMD (P = .001, r = .530), femoral neck z score (P = .001, r = .514), femoral neck T score (P = .002, r = .524), and lumbar spine BMD (P = .033, r = .334). No correlation was found between dual-energy x-ray absorptiometry measurements and the other variables (age, calcium, phosphorus, and alkaline phosphatase levels), and no results were reported for hepatitis C or HIV because none of the participants tested positive for those measures.

The most frequently reported causes of reduced BMD levels was vitamin D deficiency, low BMI, and low functional movement ability, although none of these was a strong independent risk factor in multivariate analysis, the authors reported.

They acknowledged that the results may not be generalizable to all patients because the study was conducted at a single center in Turkey.

“The results of our study emphasize the importance of early detection of comorbid conditions that decrease bone mass in severe hemophilia A patients,” they concluded.

The study was funded by the Yüzüncü Yıl University Scientific Research Project Committee. The authors reported no conflicts of interest.

SOURCE: Ekinci O et al. Haemophilia. 2019 Aug 8. doi: 10.1111/hae.13836.